MOUTH and PRICE sets

I've noticed that my MOUTH diphthong has a fronted onset before nasals.
loud [laUd]
down [d{Un]
mouth [mEUT]
Does this occur in other varieties?

I've also noticed that my PRICE dipthong has a very back onset; I've seen it transcribed as [AI] and I'm inclined to agree. I've also noticed some variation in the use of the raised allophone. In Accents of English, Wells lists some words that have an unraised /aI/ despite a following voiceless consonant, because they are 'captured' by the following stressed syllable. For me however, they almost all have the raised allophone.

bisexual [baI"sEk.Su.Uo]
citation [s6I"te.Sn=]
hypothesis [h6I"pQ.T@.sIs]
titanic [t6I"tE@.nIk]
psychology [s6I"kQ.l@.dZi]
Cyclops ["s6I.klQps]

For those of you with Canadian Raising, which allophone do you have in these words?

<<I've noticed that my MOUTH diphthong has a fronted onset before nasals.>>

Hmm, now that you mention that, I think I do have similar fronting. Usually my unraised MOUTH diphthong is [aU] (with a near-front onset), whereas before nasals, it seems like a fully fronted [{U].

(Note that here I'm differing slightly from the official chart and considering [{] to be a fully open vowel.)

loud ["laUd]
down ["d{Un]
mouth ["mEUT]

<<I've also noticed that my PRICE dipthong has a very back onset; I've seen it transcribed as [AI] and I'm inclined to agree.>>

I would transcribe my unraised PRICE diphthong as [aI], with a truly central onset. I can clearly hear a difference in the onset of my [aU] and [aI].

<<For those of you with Canadian Raising, which allophone do you have in these words?>>

I use the unraised allophone in most of those words:

bisexual [baI"sEkSu5=]
citation [saI"t_heISn=]
hypothesis [haI"p_hQ:T@sIs]
titanic [t_haI"t_h{nIk]
psychology [saI"k_hQ:l@dZi], but compare "psychic" ["s6IkIk]
Cyclops ["s6IklQ:ps] and also "nitrogen" ["n6Itr\@dZ@n]

<<I've noticed that my MOUTH diphthong has a fronted onset before nasals.>>

My dialect seems to lack such fronting, with [{U] never showing up except as an innovation brought in from outside in some particular individuals' idiolects (for instance, my sister has [{U] sporadically, but overally it is quite rare here).

<<I've also noticed that my PRICE dipthong has a very back onset; I've seen it transcribed as [AI] and I'm inclined to agree.>>

I am the opposite, having a quite front onset, and even when raised only raising to [@I] rather to something like [VI]. This is unlike my /aU/, which when unraised has a more central onset than /aI/ (generally front-central) and when raised has a backed onset- which in most speech is back-central but in very unstressed informal speech can be fully backed.

<<For those of you with Canadian Raising, which allophone do you have in these words?>>

I consistently use the raised allophones in these words:

bisexual [b@I"sEkSu:U]
citation [s@I"t_heSn=:]
hypothesis [h@I"p_haTIsIs]
titanic [t_h@I"t_hE:{~nIk]
psychology [s@I"k_ha:L\@dZi:] or [s@I"k_ha:M@:dZi:]
psychic ["s@IkIk]
Cyclops ["s@kL\aps] or ["s@IkM\aps]
nitrogen" ["n@ItSR=:dZI~:n]